The current heightened sense of security and declining cost of monitoring equipment have resulted in increased use of surveillance systems using technologies such as closed-circuit television (CCTV). Such systems have the potential to reduce crime, prevent accidents, and generally increase security in a wide variety of environments. Video surveillance systems typically include a series of cameras placed in various locations about an area of interest (e.g., a warehouse, a retail establishment, an office building, or an airport, for example). The cameras transmit video feeds back to a central viewing station (or multiple stations), typically manned by a security officer. The various surveillance feeds are displayed on a series of screens, which are monitored for suspicious activities.
Areas that are monitored with video surveillance systems often have other sensor networks available for monitoring other aspects of the environment. For example, many installations have electronic doors that report who opens them (using, for example, a “smart-card” reader system) or radio-frequency identification (RFID) systems that report when a particular object enters or leaves an area. In particular, retail stores often have a variety of data networks available in addition to video surveillance systems. Point-of-sale (POS) systems, for example, record when purchases are made, when cash drawers are opened, when returns are made, and when coupons are redeemed, among other events that can occur at a checkout or purchase area. As another example, electronic article surveillance (EAS) systems placed at exits register EAS tags as they exit the store, and generate events (either silent, audible, or both). Inventory control systems using bar-code scanning, shelf-scanning, and other techniques are also common in such environments. In addition to video surveillance, RFID systems have become increasingly popular for tracking people and/or objects throughout facilities such as office buildings, warehouses and retail establishments.
Implementing and integrating video surveillance and RFID tracking systems, POS systems, and other tracking modalities involves numerous challenges. Initially, the cameras, transmitters and other data-capture devices must be placed such that they achieve the goals outlined for the system, e.g., product tracking, theft prevention, personnel management, or some combination thereof. Often, however, the physical layout of the monitored environment does not lend itself to complete coverage. For example, small, rarely used rooms, hidden hallways, or other locations not within direct visual sight of a camera or that do not have high product traffic may be left unmonitored. This may be due to limited funds, physical characteristics of the building (walls, columns, etc.), the limited ability to monitor multiple video streams, and other restrictions. In addition, malfunctioning equipment may create temporary “dead zones” that are not covered. Unfortunately, individuals likely to attempt to misappropriate merchandise (disgruntled employees, habitual shoplifters, etc.) may be aware of the uncovered areas, and use them to advance their thefts.
In addition to the challenges relating to theft, merchandisers struggle to accurately track products as they travel about a facility. For example, most RFID implementations are limited to inventory control points such as loading docks and warehouse shelves. However, once a product leaves the “back room” and is shelved for sale, retailers lose track of the products until they “reappear” at a point-of-sale device such as a cash register or scanner. This inability to track a product from its point of entry (e.g., a loading dock) through the ultimate exit point from the facility (customer exit, shipping dock, etc.) represents a significant under utilization of RFID capability.
Current attempts to combine video surveillance systems with data from other tracking systems have not provided comprehensive, adaptive solutions that address these limitations, and most still require significant human interaction to monitor and/or coordinate the two systems. Conventional systems that attempt combine video surveillance with data from other, non-video tracking systems typically rely on a strong association (e.g., 1:1) between devices (e.g., RFID transmitters) and cameras. Although useful for purposes where limited activity is expected (intruders into otherwise restricted areas, for example), such systems cannot effectively identify and track objects in busy environments. POS applications are typically limited to cash registers located at specific check-out locations within a store. Furthermore, most video surveillance systems require some form of human interaction to positively identify subjects as they traverse the facility and move from one camera to another and to detect anomalies (e.g., suspicious behavior, missing merchandise, etc.) that prompt action. RFID transmitters generally have an effective radius that is significantly smaller than a camera's field of view, while typical video surveillance systems attempt to minimize implementation costs (and monitoring burdens) by using as few cameras as possible for a given coverage area. In retail and casino implementations, for example, this can result in dozens of people and potentially hundreds of products being within a camera's view at a given time.
Furthermore, for tracking information (whether video, RFID, and/or POS) to be used as evidence of illegal or suspicious activities (e.g., intruders, potential shoplifters, etc.), it must meet additional authentication, continuity and documentation criteria to be relied upon in legal proceedings. Tracking information that is properly annotated with date, time, and location information, and which can show a continuous stream of activity without temporal or spatial interruptions, is much more valuable as evidence than a series of non-contiguous, unmarked segments.